It is about the maps: "The Sewers", "The Apartments", "The Truck Depot" and "The Runway"from the original Left 4 Dead (these crash in SFM after porting from the game), and "Cutting Throat Creek" from Left 4 Dead 2. (Also, I have installed the L4D content pack, but it is nowhere to be found, including maps..)

I have copied over all of the assets with GCFscape (and those manually that were in the folders already) for both games. SFM is told where to look. All of the objects work great in game and all of the maps I have so far work like they should. The SFM version of Hammer loads all of the assets.

I'm at it for multiple hours for the past few days and its so extremely frustrating. I just want to be able to recompile various maps for machinima I am working on in good quality. These maps are literally the only ones I am missing for left 4 dead and I figure that I will want to port over other maps in the future as well.

Decompiling:
- Tried throwing the map in there, just leave everything and click on decompile
- Throw the map in there, manually extracted the materials on both smart extract and not
- Thrown the map in there, extracted the materials on smart extract and not, and specified the game and source 2004-2009

Recompiling:
- SFM's version of Hammer won't re-compile the map. It keeps throwing many errors at me with leaks, and other issues. It skips the light compiling and straight goes to the end. When I ask Hammer to point to me where the leak is, the window opens for the point file which basically says there is no leak. If I open this map, SFM crashes. Even keeps giving area portal errors while area portals are deleted for example
- Tried deleting all of the entities except for the props, a couple of regular lights, skybox and shadows to keep the barebones minimum. SFM loads the map, but without HDR. HDR is checked. Also tried WITHOUT HDR. Won't load HDR either. all of the console commands won't work. like mat_fullbright etc.
- Tried the approach in another topic where i would deselect things in the vis group menu, tried deselecting the props as well. It won't compile in SFM Hammer.
- L4D2 hammer compiles like normal. Tried recompiling the map in there and deleting all of the unnecessary entities and vis groups. SFM crashes after importing the map. I was lucky once with a compile, I have no idea what I did. but all of the models were black.
- Tried porting all of the game assets over to Source SDK 2013 and used both Hammer there and Hammer++, and do all of the above as well, doesn't work either. Tried Half-Life 2, TF2, to no avail..

Lastly, since L4D often works, I have tried everything above in L4D authoring tools as well. Sometimes the map loads in SFM, but without HDR. It's safe to say I need help. :(